Multivariate analysis of eshnan (Seidlitzia rosmarinus Boiss.) based on morphological characterizations

Abstract Seidlitzia rosmarinus Boiss. has been identified as one of the potential species that could be used for rehabilitating degraded desert rangelands and salt‐affected soils due to its high salinity resistance and soil‐stabilizing ability. Morphological variation of 144 accessions of this species from 14 regions of the Isfahan province, Iran was investigated. The accessions studied were significantly different in terms of the traits recorded. Three forms of plant growth habit were observed, including spreading bush, erect bush, and shrub. The range of leaf dimensions was as follows: terminal leaf length: 1.57–7.22 mm, terminal leaf width: 0.91–3.34 mm, basal leaf length: 11.84–45.27 mm, and basal leaf width: 1.32–4.18 mm. Fruit diameter (with wings) ranged from 0.19 to 12.91 mm, and 100‐fruits dry weight varied between 0.11 and 0.76 g. A dendrogram created using Euclidean distances and the Ward's method revealed two main clusters. The obtained data revealed the morphological diversity within the studied populations. The reason for such a high diversity can be explained by a low probability of gene flow among the studied accessions. This is the first report on the application of morphological characteristics in the evaluation of the phenotypic variation of S. rosmarinus. This study presented a high phenotypic diversity of S. rosmarinus germplasm that could provide useful information for conservation and selection of cross‐parents in breeding.

Iranian people used to make holy bonfire using plants growing in saline soils. They used S. rosmarinus ashes as detergent to wash their bodies and their clothing. When mixed with oil or suet, it makes high-quality soap. Today, the ash of this plant is a source of alkaline materials, used in soap and detergent industries. The ash has also antiseptic and antibacterial properties. Root tissues of S. rosmarinus have a high capacity to absorb large amounts of soil alkali metals such as Na+ and K+, which are subsequently transferred to the shoots. It seems the main mechanism of salt resistance in this plant is tolerance. Large amount of sodium is accumulated in cell vacuoles. The ash contains a large amount of sodium and potassium carbonates (Koocheki & Mahalati, 1994).
Phenotypic diversity in plants is required for populations to evolve in response to environmental changes, and its maintenance is crucial for long-term species survival. Therefore, knowledge of phenotypic variation of an endangered species under different environments is the prerequisite for understanding its genetic variation pattern, fitness, and evolutionary capacity to adapt to environmental changes, and it is crucial for their in situ conservation and management (Yang et al., 2013). Morphological evaluation and characterization are the first steps for the description and classification of germplasm (Badenes et al., 2000).
Until now, there is no published report on the evaluation of genetic diversity of S. rosmarinus. The main objective of the present work was the evaluation of morphological diversity of the S. rosmarinus populations in the Isfahan province, Iran to select the individuals to be used in the breeding programs.

| Plant material
Morphological variation of 144 accessions of S. rosmarinus from 14 regions of the Isfahan province, Iran was investigated. Geographical coordinates and altitude corresponding to collection sites are shown in Table 1. The appropriate distances were considered between the accessions in each collection site to avoid the possibility of sampling and collecting clones of the selected plants.

| The characteristics evaluated
A total of 45 morphological and pomological traits ( Table 2) were used for phenotypic evaluations. The traits such as dimensions of internode, leaf, fruit, and seed, were measured using a digital caliper.
Fruit weight was measured using an electronic balance with 0.01 g precision. In addition, the remaining characteristics were qualitatively estimated based on rating and coding ( Table 3).

| Statistical analysis
Analysis of variance (ANOVA) was performed to evaluate the variation among the accessions based on the traits measured using SAS software (SAS Institute, Cary, NC, USA, 1990). Principal component analysis (PCA) was used to investigate the relationship between the accessions and determine the main traits effective in genotype segregation using SPSS software (SPSS Inc., Chicago, IL, USA, Norusis, 1998). Hierarchical cluster analysis (HCA) was performed using Ward's method and Euclidean coefficient using PAST software (Hammer et al., 2001). The first and second principal components (PC1/PC2) were used to create a scatter plot with PAST software. Fruit diameter (with wings) ranged from 0.19 to 12.91 mm, and 100-fruits dry weight varied between 0.11 and 0.76 g. Seed wing shape was predominantly blowing (100 accessions), seed wing apex was round the majority of accessions (98), and seed wing color of most of the accessions (72) was pink, and the range of seed wing number was 4-7. Also, the seed color was gray (90), and black (50) (

TA B L E 4 (Continued)
with fruit diameter (with wings) (0.85), seed wing length ( The S. rosmarinus is a xerophytic desert salt-tolerant plant having genes responsible for its resistance to salt and drought stresses. It can serve as a very useful tool in the hands of plant breeders to produce agricultural crops resistant to these stresses. It accumulates copper and manganese at nontoxic levels, and has a high level of protein (7%) and 80% digestible organic matters (Koocheki & Mahalati, 1994). With these nutritional properties, it can be used as forage for livestock especially for camels in severe dry and saline desert conditions. Further therapeutic properties of this plant should be explored, for example, for the treatment of acnes.
The leaves of S. rosmarinus accumulate a large amount of soda compounds which can be used in several industries such as making soaps and detergents, pottery, ceramics, in sugar factories (sugar crystalinization), and copper bleaching. The potential of this species in environmental protection such as wind break and preventing soil erosion should not be overlooked (Kurkova et al., 2002).

| CON CLUS ION
This is the first report on the application of morphological charac- F I G U R E 3 Ward cluster analysis of the studied S. rosmarinus accessions based on morphological traits using Euclidean distances.
domesticate these valuable species. The presence of variation is crucially vital to preserving the evolutionary ability to live under a dynamic climatic condition. The phenotypic diversity among these individuals could provide useful information for conservation and selection of cross-parents in breeding.

ACK N OWLED G M ENT
None.

CO N FLI C T O F I NTE R E S T
The authors declare no conflict of interest.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon reasonable request.

R E S E A RCH I N VO LV I N G H U M A N PA RTI CI PA NTS A N D/ O R A N I M A L S
None.

I N FO R M E D CO N S E NT
None.